This invention relates generally to a device: for exercising the leg and/or providing rehabilitative therapy of a patient""s leg and knee joint. In many situations, it is desirable for a patient to manually exercise the knee joint. Two such situations are anterior crucial ligament (ACL) knee surgery and knee replacement surgery, where the range of motion of the knee joint must be increased following the surgery to allow the patient to perform normal activities. The process of regaining the full range of motion of the knee joint is slow and a device such as the present invention speeds that process by allowing the patient to manually extend the leg through the full range: of motion. This therapy normally comes with some discomfort, so a manual device is preferable to an automatic exerciser, so that the patient may control the amount of pressure applied to exercise the knee joint or straighten the leg.
In the United States, there are over one million ACL and knee replacement surgeries each year. Outside of the U.S., however, there are over ten million ACL and knee replacement surgeries each year. The present invention provides a much needed, simple, and relatively inexpensive device for not only rehabilitative therapy following ACL or knee replacement surgery, but also for exercising a patient""s leg generally.
The prior art contains numerous devices for exercising the leg and/or rehabilitating the knee joint of a patient. However, none of the prior art combines the simplicity, high degree of adjustability, effectiveness, and low cost of the claimed invention.
U.S. Pat. No. 5,662,562 to Wohlenberg teaches a leg exercise device that can be placed above or below the knee.
U.S. Pat. No. 5,236,333 to Barba, Jr. teaches a leg exerciser that is placed directly on the knee joint and operated by the user.
U.S. Pat. No. 4,844,454 to Rogers teaches a knee therapy device using two platforms that secure the upper and lower portions of the leg.
U.S. Pat. No. 5,254,060 to Bohannon teaches a motorized apparatus to exercise the legs or arms of a patient.
U.S. Pat. Nos. 5,896,459 and 5,254,067 to Habing et al. teach leg exercise devices that use pistons or a flywheel and generator to provide resistance to leg movement.
U.S. Pat. No. 5,803,883 to Patrylak et al., U.S. Pat. No. 5,338,274 to Jones, and U.S. Pat. No. 4,542,900 to Ray teach exercise devices that employ weights, similar to machines found in gymnasiums.
U.S. Pat. No. 5,855,538 to Argabright teaches a device that allows the user to position his feet in members that slide along tracks to extend the legs.
U.S. Pat. Nos. 5,685,830, 5,456,268, 5,395,303, 5,285,773, 5,213,094, and 5,167,612 to Bonutti teach complex mechanical devices utilizing wires, pulleys, and cuffs to exercise or rehabilitate a patient""s arm, although ""094 discloses application to a knee joint as well.
U.S. Pat. No. 5,088,731 to Carpenter teaches a device for exercising the wrist of a patient.
U.S. Pat. No. 5,611,770 to Tesch teaches a device for exercising the foot or ankle of a patient.
U.S. Pat. No. 5,509,894 to Mason et al. teaches a device that holds the leg in a suspended position and allows the user to pull a handle to straighten the leg, with the only downward force being applied to the leg being that of its own weight.
U.S. Pat. No. 5,013,037 to Stermer teaches a physical therapy device worn by a patient to provide resistance to certain directions of motion.
While not limited to therapy, this device finds particular application in rehabilitative therapy for patient of knee surgery, as often times the ligaments in the knee joint will heal in a contracted state, and therefore must be stretched in order to regain the full range of motion in the patient""s knee joint. Accordingly, It is the object of the present invention to provide a simple, effective, and inexpensive device to exercise the legs and knee joints of persons of varying height, leg length, and upper body strength.
Another object of the present invention is to enable self-directed movement of a leg by a patient that is unable to do so under his own leg muscle control, such as where a person has experienced either temporary or permanent paralysis of the lower body. In such situations, it is desirable to manually exercise the patient""s immobile limbs.
The present invention is directed to a lever with a handle on one end with a harness means attached to the other end. A fulcrum is attached to a slider assembly located in the middle portion of the lever. The slider assembly and fulcrum can be adjusted to provided optimum placement of the fulcrum on the patient""s leg.
Additionally, the slider assembly and fulcrum can be adjusted to provide the user with greater leverage. While the present invention can be used with the assistance of weights, which would be hung on the handle, it is generally unnecessary to use weights, because of the increased leverage from the present invention. By allowing the user to increase the horizontal distance between the fulcrum and the point where the slider assembly attaches to the lever, thereby increasing the moment arm, the user can effectively increase the leverage of the device by 300-500%. This is particularly useful where the user does not have a great deal of upper body strength or the limb being exercised or straightened requires a higher level of pressure to effectively articulate the limb.
A harness means is located at the end of the lever opposite the handle and is used to hold the foot and ankle in place. The harness means in the preferred embodiment has a means of securing the foot, namely a ring that is used to cinch the two straps, which form the harness. The harness is not only effective to support the foot and ankle, but is also comfortable for the user. The harness allows the users foot to pivot and turn while still providing the support necessary to effectively exercise the leg or knee joint.
A means for fixing the position of the slider assembly and fulcrum relative to the elongated member, such as a hand-knob or other mechanical means, is also contemplated in the present invention. Other mechanical means could include a rubber grommet affixed to the interior diameter of the slider, which would prevent (except through deliberate positioning by the user) said slider from moving along the elongated member, or holes through said elongated member and a hole in the slider through which a pin could be inserted, thereby fixing their relative positions. The various possible means for fixing the position of the slider relative to the elongated member, although contemplated in the invention, are not shown in the drawings.